We currently have a pair of OSFF. As mentioned, they require multiple feedings per day of a variety of foods, and are best kept in a species tank or at the very least, a VERY passive setup.
Renee actually weaned ours onto frozen, and I can tell you that I've never seen her work so hard to wean fish (and she's really good at it). I'd actually find her with the covers pulled over her head (the fish were in our bedroom) peeking out a tiny hole just to see if the fish would even take a small peck at whatever food was offered (in addition to the live acros we had to keep them eating something while they learned to eat other foods). Two years later, they're doing fine, but it took a LOT of work to get them eating and get some weight back on them.
There are a couple of extensive threads on them in the Reef Fishes forum.